As the demand for metals continues to grow and as the availability of high-grade deposits decreases, research studies continue to provide better and less expensive apparatus and methods for recovering metal values from low-grade mineral deposits.
One example of a successful apparatus and method is Harvey et al, U.S. Pat. Nos. 3,875,041, issued Apr. 1, 1975, and 3,928,152, issued Dec. 23, 1975, both of which are assigned to the assignee of this application. Harvey et al describe apparatus and methods for improving the electrolytic recovery of metal employing electrolyte convection. The apparatus and methods described in the Harvey et al patents increase the rate at which metal values are deposited, by carefully controlling the process parameters and the interelectrode structure of the electrolytic cell. The result is a lower cost per pound of recovered metal.
Apparatus and methods disclosed in the Harvey et al patents, which are hereby incorporated by reference, require careful control of the distance between the cathode and anode faces, the use of sheets of gas bubbles to maintain agitation and convective motion of the electrolyte, and the use of baffles to control the flow of electrical currents through the electrolyte and hence to control the deposition of metals onto the cathodes.
However, the apparatus and methods described and claimed in the Harvey et al patents result primarily from work performed in a laboratory environment and hence the apparatus and methods are not necessarily carefully tailored to a commercial manufacturing environment.
It is therefore a principal object of the invention to provide apparatus and methods more suited to commercial practice than those disclosed by Harvey et al. Other objects of the invention include providing apparatus and methods which are rugged, reliable, simple to construct and implement, and inexpensive to use. Yet other objects of the invention include providing apparatus and methods which increase the speed at which metal values may be stripped from the cathode members according to the apparatus and methods of the Harvey et al patents and which provide higher metal output than presently used commercial processes. A further object of the invention is to improve and simplify cell loading and unloading to avoid damage to the anodes and cathodes.